Catalytic converter for exhaust gases

ABSTRACT

A catalytic converter for treating exhaust gas streams which has a removable catalyst cartridge embodied therein and which is designed to be connected directly to the exhaust ports of an internal combustion engine.

United States Patent De Palma et al.

[54] CATALYTIC CONVERTER FOR EXHAUST GASES [72] inventors: Ted V. DePalma, Roselle; Robert S. Carleton, Libertyville, both of 111.

[73] Assignee: Universal Oil Products Company, Des

Plaines, Ill.

[22] Filed: Sept. 18, 1969 211 App]. No.: 858,918

[52] US. Cl. ..23/288 F, 23/2 E, 60/29 B01] 9/04, BOld 53/34, FOln 3/16[58] Field of Search ..23/288, 228 F, 2 E;

55/DIG. 30, 517; 60/29, 30

[ 5] Feb. 22, 1972 [56] M References Cited UNITED STATES PATENTS3,247,666 4/1966 Behrens ..60/30- 3,184,291 5/1965 Calvert 23/288 FHarman-Ashley Schnabel .60/ 30 Primary ExaminerJames 1-1. Tayman, Jr.Att0rney.lames R. Hoatson, Jr. and Philip T. Liggett ABSTRACT Acatalytic converter for treating exhaust gas streams which has aremovable catalyst cartridge embodied therein and which is designed tobe connected directly to the exhaust ports of an internal combustionengine 8 Claims, 5 Drawing Figures PATENTEDFEBZZ 972 3, 644.098

SHEET 1 BF 2 FIGURE 3 l2 7 FIGURE 2 INVENTORS:

TED l. DEPALMA ROBERT S. CARLETO/V A T TOR/VEYS PATENTEUFEBZZ I972 3,644. 098

sum 2 UF 2 lOl Ill I2" IO FIGURE 4 FIGURE 5 IN V EN TORS TED V. DEPALMABy ROBERT S. CARLETON J mzr A r TORNE rs CATALYTIC CONVERTER FOR EXHAUSTGASES This invention relates to an improved form of a converter adaptedto hold a bed of solid contact material to treat an exhaust gas stream.More specifically, the present apparatus provides the means for thecatalytic conversion and purification of the exhaust gases from aninternal combustion engine, with the utilization of a design thatprovides for easy placement and removal of the catalytic bed therein andalso that overcomes the problem of heat losses by being adapted fordirect connection to the exhaust ports of the engine.

The desirability for removing, or converting to harmless form, thenoxious components of vehicular exhaust gases has been well established.The principle constituents of such gases include the several oxides,nitrogen, carbon monoxide, and unburned or partially burnedhydrocarbons; these materials, upon being expelled into the atmosphere,are known to be harmful to human health, Under the action of sunlightthese emissions can combine to produce a wide variety of noxious,irritating compounds popularly and generally referred to as smog.

it has long been recognized that catalytic devices located in theexhaust system of an internal combustion engine can overcome the problemof smog and of atmospheric contamination. In the usual catalytic method,the hot gases issuing from the motor exhaust manifold are passed througha fixed catalytic bed which effects more or less complete oxidation ofthe carbon monoxide and unburned hydrocarbons present in the exhaustgases, converting them to carbon dioxide and water. Oxides of nitrogenare also converted to nitrogen and oxygen. Sometimes the exhaust gasesare mixed with a quantity of secondary or combustion air before beingintroduced into the catalytic bed, but with modern fuel-air ratios inpresent carburetion systems, this requirement is no longer consideredabsolutely necessary. Generally, the use of a catalytic method andapparatus provides for the initiation of the oxidation reaction at lowertemperatures than would be otherwise possible without the use of acatalytic agent, and its use will also eliminate the need for sparkplugs or other ignition means which are necessary in most types ofafterburners or other apparatus which depend strictly upon thermalconversion conditions.

it has been found that one of the difficulties encountered in theutilization of catalytic converters for affecting the oxidation ofautomotive exhaust gases arises by the necessity to achieve a highenough temperature in the catalyst bed to establish initial oxidationand also to supply adequate, sensible heat to the catalyst after enginewarm up. in other words, when an automobile is initially started from acold start, then for a period of from 2 to perhaps minutes, dependingupon the manner of operating the automobile, the catalyst may remainrelative cool and be unable to burn the residual combustible componentseffectively within the converter, thus permitting high emissions ofunburned hydrocarbons, etc., through the system into the atmosphere.

in addition, it has been found that in most cases, catalytic reactorswill operate at higher levels of efficiency, if provided with anadequate supply of sensible heat. For instance, it has been found thatcertain fuel additives and/or lube oil compounds, containingtetraethyllead, lead alkyls, barium, and other metal constituents, willnormally deactivate or poison emission control catalysts. Hightemperature operations will prevent this sort of catalyst poisoning bysuch metals or fuel additives.

Heretofore, catalytic reactors which have been used on automotivevehicles have usually been designed for installation somewhere near thenormal spot reserved on the vehicle for the muffler. However, when theconverter is placed near the normal spot reserved for a muffler, theperformance of the converter suffers at the time of initial oxidationand after warmup mainly because of the heat losses from the piping whichextends from the engine to the muffler-converter. Various schemes havebeen used to minimize heat losses, including insulation, heating ofsecondary combustion air, etc. Conventionally. all multicylinder engineshave an exhaust manifold which functions as a collecting chamber for theexhaust gases which issue from the cylinders. These gasses are thenconducted through a pipe to the converter muffler, after which anexhaust pipe conducts them to the atmosphere. The present invention isan attempt to remedy the problems due to heat loss and catalystdeactivation in that it provides for a catalytic converter that doublesas the exhaust manifold in the engine.

It is further noted that after a period of operating time, the catalystemployed in a converter may still become contaminated, especially withinengine systems utilizing a leaded gasoline. After contamination, theefficiency of conversion drops to such an extend that the undesirablehydrocarbons and carbon monoxide are emitted to the atmosphere withoutbeing converted. Thus, this present invention attempts to include thedesirous characteristics of a converter system which has an arrangementthat permits easy removal of the catalytic bed therein, thereby allowingfor the replacement of contaminated catalyst particles.

Also, high temperatures, substantially in excess of those encounteredwithin conventional exhaust systems, are produced as a result of theexothermic oxidation reactions taking place within and around thecatalyst bed. Depending upon the particular catalyst employed and theproximity to the exhaust ports of the engine and upon the operation ofmotor vehicle itself, converter temperatures may run as high as l,200 tol,800 F. Because of these high temperatures, converters have beenrapidly, and virtually completely destroyed by deformation, split seams,etc., as a result of uneven thermal expansion. The converter disclosedherein therefore embodies a design that provides for equalization ofthermal stresses, whereby differential stresses within its walls arekept well within the elastic limit of the material of construction.

Thus, it is a principal object of this invention to provide an efficientcatalytic converter that is located in close proximity to the exhaustports of the engine, thereby eliminating the need for insulated pipesand/or heating of secondary combustion air and thereby preventingdeactivation of the catalyst particles by tetraethyllead and othermetals. More specifically, it is an object of this invention to providefor a catalytic converter for the conversion of automotive exhaust gasesthat also serves as the exhaust manifold of an engine.

It is also an object of this invention to provide for a catalyticconverter that encases a removable catalyst retaining cartridge, its usethus permitting easy placement and removal of the subdivided catalystparticles.

It is a further object of this invention to provide a catalytic mufflerwhich is constructed in such a manner that the various components willbe capable of expanding and contracting relative to each other as thetemperature of the apparatus fluctuates.

In a broad aspect, the present invention provides for a catalyticconverter for containing subdivided catalyst particles for treating anengine exhaust stream and adapted for direct connection to the exhaustports of an engine, which comprises, in combination, an elongated outerhousing having a removable cover plate, an interior perforated cartridgefor containment of said catalyst particles having an inlet perforatewall section and an outlet perforate wall section to provide for exhauststream flow therethrough, said perforated cartridge removably disposedin said housing and spaced with respect to the interior of said housingto form an inlet manifold section and an outlet manifold sectiontherein, plural inlet means through said housing and havingcommunication with said inlet manifold section and said inlet wallsection, said inlet means spaced and sized for direct connection to theexhaust ports of an engine, and treated gas outlet means from saidhousing and having communication with said outlet wall section via saidoutlet manifold section.

In a preferred form, the elongated housing comprises a simplyconstructed cast unit. The plurality of inlet means are adapted toconnect to the exhaust ports of the engine and are introduced into theelongated housing through a horizontal top portion thereof. The inletmeans may be so designed so as to permit casting during the castingoperation of the outer housing, thereby establishing a single unitconstruction. In this preferred form, the elongated housing has anarrower longitudinal section extending along its lower side, thusproviding the outlet manifold section and a cartridge placement shelf.This section is also east along with the outer housing as one piece. Theoutlet manifold may be provided with a pipe extension having flangedends for connection to the downstream end of an exhaust system. One sideof the outer housing is open ended with flanged edges, having threadedholes therein, to establish connecting means for a cover plate, whichpermits access to the catalyst cartridge. In one embodiment the catalystcartridge is substantially rectangularly shaped with the side wallportionsabutting the interior of the elongated housing. its depth isshorter than that of the internal depth of the elongated housing,thereby providing the manifold section between the inlet perforate wallsection and the inlet means. The cartridge is placed on the bottom shelfsurface of the elongated housing, formed by the extending longitudinalsection.

The outlet perforate wall section communicates with the longitudinalsection extending along the one side of the housings. Transverseprojections or other suitable holding means are located along theinterior walls of the outer housing and cover plate, so as to hold thecartridge in place when installed and to prevent passing of untreatedexhaust gases between the cartridge side wall portions and the walls ofthe housing. The perforate sections of the cartridge may be curvedslightly to enhance their strength.

In another embodiment, the inlet perforate wall section is curved to agreater extent and in fact is ofa segment-cylinderform. By referring to"segment-cylinder-form" it is meant to encompass a portion of acylinder; i.e., a cylinder being defined by a line moving parallel to afixed line. A semi-circular-cylinder-form would be one special exampleof such 21 segment-cylinder-form. In this embodiment, the outletperforate wall section is also of a segment-cylinder-form and is spacedinwardly from the inlet perforate wall section. Of course, to form thecartridge end partition means must be connected to the perforatesections for establishing the structure and also for preventing catalystparticles from flowing through the ends. In one embodiment utilizing thesegment-cylinder-form perforate walls the convex surface of the inletperforate wall section contacts the inlet manifold section. Preferablyin this embodiment, the longitudinal ends of the resulting cartridge areplaced on the cartridge placement shelf and thus the concave surface ofthe outlet perforate section communicates with the longitudinal sectionextending along the one side of the housing.

In another embodiment utilizing the segment-cylinder-form perforatesections, the concave surface of the inlet perforate section contactsthe inlet manifold section. In this embodiment, the longitudinal ends ofthe resulting cartridge are attached to the housing near the inletmeans. There is no need to have a longitudinal section extending alongone side of the housing because there is no need for a placement shelfon the outlet side thereof.

In both of the embodiments using the segment-cylinderform perforatesections, the resulting cartridge may be held in place by theutilization of a tongue and groove arrangement, whereby the cartridgemay be slid into the housing and held in place by the tongues andgrooves. Of course, other suitable holding means within the housing maybe provided for maintaining the cartridge in place.

Although not contemplated as being necessary in all applications, asecondary air inlet means may be provided in conjunction with thisparticular manifold converter. Also baffle means may be located withinthe inlet manifold section to establish uniform flow across theperforate inlet wall section of the cartridge. These baffle means maytake various forms, as for example, they may be perforated inserts orplugs that can be placed within each individual inlet means. The presentimproved design may be better explained, as well as further advantageousfeatures set forth, by reference to the accompanying drawing and thefollowing description thereof.

FIG. 1 is a longitudinal partial sectional view of one embodiment of theconverter of this present invention.

FIG. 2 is a sectional view of the embodiment of FIG. 1 as taken throughline 22.

FIG. 3 is a sectional view of an inlet conduit with a baffle pluginserted therein.

FIG. 4 is a sectional view of an embodiment of the converter of thisinvention utilizing an in-to-out segment-cylinderform cartridge.

FIG. 5 is a sectional view of an embodiment of the converter of thisinvention utilizing an out-to-in" segment-cylinderform cartridge.

Referring now more particularly to FIGS. 1 and 2 of the drawings, thereis indicated one embodiment of a catalytic converter apparatus shownembodied within a casing or outer housing 1. Outer housing 1 in thisparticular arrangement has been formed by a casting operation known tothose skilled in the art, and is of a suitable material adapted forcasting, such as an iron alloy. The front face of outer housing 1 hasflanged edges 2 provided around its entire periphery. Flanged edges 2are provided with spaced-apart threaded holes 3, to be used forconnection of the cover plate thereon. The cover plate 4 is designed tocompletely enclose the space within housing 1 and has holes 5 thereonfor inserting of bolts 6. A gasket or other suitable sealing means 7,made of a material capable of withstanding temperatures to 2,000 F., isprovided between cover plate 4 and the flanged surfaces or edges 2.

In this particular embodiment the outer housing 1 has a lowerlongitudinal section 10, which is ofa narrower cross section than is themain rectangular portion of housing 1. Thus is provided an internalsurface 11, which serves as the surface of placement for the catalystcartridge. The space 12, established by lower longitudinal extension 10,provides the outlet manifold section for the treated exhaust gases. Anarrower cross section outlet pipe means 13, having flanged portions 14for direct connection to the conventional exhaust system of an internalcombustion engine, is located at the left end of manifold section 12,although it may be disposed at any location thereof.

Located within outer housing 1 and designed to abut walls 20, 21, 22,and 23, thus preventing any quantity of exhaust gases from passingthereby, is catalytic cartridge 24, shown containing subdivided catalystparticles 25. For most efficient converter operations, the cartridgeshould be filled to capacity. It is not intended to limit this improvedtype of catalytic converter to any one particular type of oxidationcatalyst, inasmuch as there are various known effective and efficientcatalyst compositions. Suitable oxidation catalysts include the metalsof Groups I, V, VI, VII, and VIII of the Periodic Table, particularlychromium, copper, iron, nickel, and platinum. These components may beused singularly, in combinations of two or more, etc., and willgenerally be composited with an inorganic refractory oxide supportmaterial, such as alumina, silica alumina, silica alumina zirconia,silica-thoria, silica-boria, and the like.

The cartridge, as shown in FIGS. 1 and 2, has imperforate sidewallportions abutting walls 20, 21, 22, and 23 of housing 1. The top andbottom walls 27 and 28, are perforate wall sections which have beenattached permanently to the sidewalls, after the catalyst particles 25were inserted. Although not shown, it is contemplated that theconstruction of cartridge 24 will be such that the construction willprevent buckling during the operation of the converter. This may beaccomplished in various ways. For example, the walls of the cartridgemay be accordioned along their length so as to absorb any expansion dueto temperature differentials. Also contemplated as being within thescope of this present improvement is a cartridgetype construction thatembodies slotted wall sections to permit the various sections to beslidably supported within each other. In addition, it is contemplatedthat instead of having permanent enclosed particles. he cartridge beconstructed in such a way as to permit opening and closing of at leastone wall portion, thereby permitting access to remove contaminatedcatalyst particles and replace them with rejuvenated particles.

The cartridge is inserted into housing 1 via the opening in the front ofhousing 1, and, as heretofore described, placed on surface 11 to abuthousing 1 at 20, 22, and 23. Also noted are projections 29 located oncover plate 4 and projections 29' located on the inner walls of outerhousing 1. These projections serve to hold the cartridge 24 onto surface11 when outer housing 1 is sealed by cover plate 4 and serve also as ameans to prevent exhaust gases from passing thereby. Gasket 7 is theninserted onto flanged pieces 2, cover 4 is inserted over this gasket,and both are bolted into place via bolts 6, to abut cartridge 24 at 21.it is to be noted that the cartridge should not be so tightly abuttedagainst the walls of the hous ing as to foreclose any expansion.

Horizontal plate 28 has apertures 31 provided therein. It is also .notedthat, similarly, plate 27 has apertures 30 located along its length.Thus is established a cartridge having an inlet perforate wall section27 and an outlet perforate wall section 28 to establish flow of theexhaust stream through the subdivided catalyst particles 25. Thecartridge is disposed within housing I so that the top inlet perforatewall section 27 is spaced from the housing and particularly from theinlet means introducing the exhaust steam into the housing, therebyestablishing an inlet manifold section 35.

The inlet means comprises in this particular embodiment four conduits36, 37, 38, and 39, which are spaced apart so as to coincide with theexhaust ports of an internal combustion engine. Of course thisparticular spacing should not be considered as a limiting factor uponthe present invention for, as shown, this spacing is merely aschematical representation, and, of course, the spacing will depend uponthe model, make and type of engine the converter is to be used inconjunction therewith. Necessarily, flanged portions are provided oneach conduit so as to establish a connecting means to the exhaust portsof the engine. It is noted that these conduits have been cast in thisparticular embodiment at the same time as the outer housing 1, thusestablishing a one-piece construction. These conduits communicate withinlet manifold section 35 via ports 40. 41. 42 and 43 through the top ofhousing 1. Of course, the introduction into inlet manifold section 35should not be considered limiting upon this present invention, forintroduction into manifold section 35 can be brought about from the backof housing 1, or for that matter, from the top at an angle to thehorizontal.

It is felt that in some cases the direct downward flow of exhaust gasesinto the catalytic bed through the apertures 30 and plate 27 may be tooconcentrated. in addition, it has been found that a converter should bearranged so that uniform distribution of exhaust gas flow through thecatalyst bed is maintained in order to achieve maximum catalyst life andmaximum conversion. Therefore, it is contemplated that baffle means maybe utilized within the converter of this present invention. Such bafflemeans may take various forms. As for example in FIG. 3, one such form ofa baffle means is illustrated. it consists of a plug or insert 50 with aplurality of apertures 51 distributed over its surface. Insert 50 isforce fitted into a conduit 36 and thus provides a means whereby thevelocity head of the exhaust gases, rushing through theconduit, isreduced to a pressure head, thereby establishing more uniformdistribution within manifold 35, and, consequently, through the catalystmaterials within cartridge 24. This particular form of baffle meansshall not be considered limiting, for others are contemplated, c.g., aflat plate spaced from the inlet ports may be attached permanently tothe interior walls of housing 1.

in FIGS. 4 and 5 there is indicated an alternate arrangement of theconverter of this invention utilizing a segment-cylinderform catalystcartridge. In other words, the cartridges 24' and 24" have been formedby segment-cylinder-form perforate wall sections 60 and 61 in HO. 4 and62 and 63 in FIG. 5. in these embodiments, the wall sections have asemicircular shape with straight extensions 64 and 65. The cartridge ismade rigid by end partition means 66 and 67 on longitudinal edgesthereof and by other similar partition end means on the transverse endsthereof (not shown). These end partition means also serve to prevent thecatalyst particles from falling out of the cartridge.

The use of a curved or segment-cylinder-form partition plate has twodistinct advantages. First, it increases the strength of the cartridgeand prevents the perforate sections from flexing laterally. Lateralflexure has been known to crush catalyst particles within a catalystretaining bed. A second advantage is in the configuration ofthe beditself. In other words, a curved bed will provide maximum amount ofcatalyst volume in a minimum-sized bed and therefore a more efficientconverter.

In these embodiments, the cartridges are inserted through an open end ofthe outer housing I and 1'. After insertion, cover plates 4' and 4" andcorresponding sealing gaskets are secured to the flanged portions 2' and2" of the housing. Actually, in these embodiments the cartridges areheld in place by a tongue and groove system. In FIG. 4, the tongue andgroove system is established by transverse pieces and 81 which form agroove 82 on both sides of the inlets. The tongue portion of the systemis formed by the end partition means 66 which overlap the imperforatepartitions to form the tongues 83. Thus, the cartridge 24 is merelyslipped into the groove 82 and is thus held in place. Of course, to holdthe cartridge in a rigid manner it may be bolted to the housing at oneof its ends. Thus, it is held in place in a rigid manner but since it isonly bolted at one place, it is free to expand in the groove 82.Similarly, the cartridge 24" of FIG. 5 is held within the housing 1" bya system of tongues and grooves. in this instance. transverseprojections 84 are located adjacent to the longitudinal extension 10'forming the outlet manifold section. These projections form a groove 85on both sides of the longitudinal section 10'. Again, the end partitions67 overlap the perforate partitions to form the tongue 86. Thus,cartridge 24" is merely slipped into the groove 85. lt may also bebolted into place to maintain it in a rigid state.

it is also contemplated that the particular converter of this inventionbe supplied with a source of secondary air, although it is notconsidered necessary in most applications, especially in light of therecent use of carburetion systems that supply excess air initially tothe engine. The supply of secondary air may be established by simplyinserting a conduit having communication with exterior of the housinginto the inlet manifold section or by a more sophisticated utilizationof valves, pumps,

etc.

From the foregoing description, it is seen that this present inventionprovides for a converter that because of its location, provides for hightemperature, at the inlet of the catalyst section. High temperatureswill permit lower net emissions of undesirable components in an exhauststream and will also permit the use of small converter configurations,which is desirable in light of the relatively small dimensions ofpresent day engine compartments. The removability of the cartridge alsoenables the quick and inexpensive replacement of catalyst particles.Such a design will enable the unskilled person to rejuvenate the systemby mere removal and replacement of the cartridge. The old cartridge,thus removed, can either be discarded, or if its design permits, be sentto the manufacturer thereof and its contents removed and replaced. Thisparticular invention also allows for installation of expansiblecartridges, thus preventing damage due to temperature differentials. Theslip-fit of the cartridge within housing 1 will also prevent expansionproblems from developing.

It is also considered as within the scope of-this present improveddesign and construction to provide for a covering of the outer housing 1with a suitable insulatingmaterial, such as asbestos, mineral wool, orthe like. in order 'to maintain the maximum amount of heat within thecatalyst cartridge, although it is found that in utilizing ,the improvedconverter that the amount of insulation necessary will not be as greatas was the case within the converter-muffler type reactors as were usedheretofore at zones remote from the motor, and in most instances will beneeded only as a heat protection means.

It may be understood that various minor modifications in the design andor location of the various portions of this apparatus may be made withinthe scope of the present invention. As for example, there may be avariation in the shape and spacing of the cartridge from that indicatedon the drawing, or in locating and designing the outlet manifold section12, as well as with respect to sizing and positioning of the ports intothe inlet manifold section. 1t is also noted that in some instances thecartridge may be reinforced with stiffening members contained within thecartridge itself. The apertures 30 and 31 located on the horizontalplates of cartridge 24 will of course be sized in relation to the sizeof the catalyst particles which are to be maintained within theapparatus. The physical shape for catalyst particles may be such thatthey are in the form of spheres, cylinders, orpellets, typically havinga dimension of 1/16 to 541 inch, although particles of larger or smallerdimensions may be employed where desirable. Mixed sizes of catalyst maywell be utilized, especially as a means to start their initial oxidationprocess. Also. as indicated hereinbefore, it is not intended to limitthe present invention to any one type of catalyst.

For most efficient operations the catalyst cartridge should bemaintained full of catalyst particles to prevent bypass of exhaustgases. Thus, it is also contemplated that a reservoir means be providedconnective with the catalyst cartridge for maintaining a filledcartridge. The embodiments of FIGS. 4 and 5 are especially well suitedfor embodying such a reservoir means. in these embodiments the reservoirmeans 90 and 91 have been formed by connecting transverse sections 92and 93 and 94 and 95 within the catalyst cartridges. These sections areprovided with a plurality of openings 100 and 1101 along their length toprovide communication of the catalyst particles from the reservoir meansinto the main body of the cartridge. Of course, the cartridgesthemselves do not have any perforations in their walls in the region ofthe reservoir means.

We claim:

1. A catalytic converter for containing subdivided catalyst particlesfor treating an engine exhaust stream and adapted for direct connectionto the exhaust ports of an engine, which comprises, in combination, anelongated outer housing having a removable cover plate, an interiorperforated cartridge for containment of said catalyst particles havingan inlet perforate wall section and an outlet perforate wall section toprovide for exhaust stream flow therethrough, said perforated cartridgebeing removably disposed in said housing and spaced with respect to theinterior of said housing to form an inlet manifold section and an outletmanifold section therein, said elongated housing having a longitudinalsection extending along one side, said longitudinal section having anarrower cross section than the main body thereof to form said outletmanifold section and to form a cartridge placement shelf in that saidlongitudinal section longitudinally opposes said outlet perforate wallsection, plural inlet means through said housing and havingcommunication with said inlet manifold section and said inlet wallsection, said inlet means spaced and sized for direct connection to theexhaust ports of an engine, and treated gas outlet means from saidhousing having communication with said outlet wall section via saidoutlet manifold section.

2. The catalytic converter of claim 1 further characterized in that abaffle means is provided in the inlet manifold section thereof forestablishing uniform gas flow from said plural inlet means through thecatalyst cartridge.

3. The catalytic converter of claim 1 further characterized in that saidperforated cartridge is substantially rectangularly shaped and hassidewall portions abutting the interior of said elongated outer housing.

4. The catalytic converter of claim 1 further characterized in that theinlet perforate wall section is of segment-cylinderform, the outletperforate wall section is of segment-cylinderform, spaced inwardly fromsaid inlet perforate wall section,

end partition means are connected to said perforate sections forpreventing catalyst particles from flowing through the ends thereof, andin that the convex surface of said inlet perforate wall section contactsthe inlet manifold section.

5. The catalytic converter of claim 1 further characterized in thatholding means is provided within said housing for maintaining saidcartridge in place.

6. The catalytic converter of claim 1 further characterized in that saidoutlet perforate wall section is of a segmentcylinder-form, said inletperforate section of segmentcylinder-form spaced inwardly from saidoutlet segmentcylinder-form section, end partition means are connectedto said perforate sections for preventing catalyst particles fromflowing through the ends thereof, and in that the concave surface ofsaid inlet perforate section contacts the inlet manifold section.

7. The catalytic converter of claim 6 further characterized in that aholding means is provided within said housing for maintaining saidcartridge in place.

8. The catalytic converter of claim 1 further characterized in that areservoir means is provided connective with said catalyst cartridge formaintaining a filled cartridge.

2. The catalytic converter of claim 1 further characterized in that abaffle means is provided in the inlet manifold section thereof forestablishing uniform gas flow from said plural inlet means through thecatalyst cartridge.
 3. The catalytic converter of claim 1 furthercharacterized in that said perforated cartridge is substantiallyrectangularly shaped and has sidewall portions abutting the interior ofsaid elongated outer housing.
 4. The catalytic converter of claim 1further characterized in that the inlet perforate wall section is ofsegment-cylinder-form, the outlet perforate wall section is ofsegment-cylinder-form, spaced inwardly from said inlet perforate wallsection, end partition means are connected to said perforate sectionsfor preventing catalyst particles from flowing through the ends thereof,and in that the convex surface of said inlet perforate wall sectioncontacts the inlet manifold section.
 5. The catalytic converter of claim1 further characterized in that holding means is provided within saidhousing for maintaining said cartridge in place.
 6. The catalyticconverter of claim 1 further characterized in that said outlet perforatewall section is of a segment-cylinder-form, said inlet perforate sectionof segment-cylinder-form spaced inwardly from said outletsegment-cylinder-form section, end partition means are connected to saidperforate sections for preventing catalyst particles from flowingthrough the ends thereof, and in that the concave surface of said inletperforate section contacts the inlet manifold section.
 7. The cataLyticconverter of claim 6 further characterized in that a holding means isprovided within said housing for maintaining said cartridge in place. 8.The catalytic converter of claim 1 further characterized in that areservoir means is provided connective with said catalyst cartridge formaintaining a filled cartridge.